<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        alert('haha');
    </script>
    <style>
        *{
            margin: 0px;
            padding: 0px;
        }
    </style>
</head>
<body>
    <input type="button" value="点我" onclick="alert('hehe')">
    <script src="./code01.js"></script>
</body>
</html>